Based on this data, we were able to find the most
disproportionately popular major (among majors with at least
1,000 degree holders) in each state. These are degrees for which
the rate of people holding that degree in a state is much higher
than the rate of people holding that degree in the US overall, as
explained in more detail below:

Business Insider/Andy Kiersz, data from
Minnesota Population Center IPUMS

These are not the most common degrees held by the residents of
the states, but instead degrees held at a disproportionately high
rate. For example, 23,977 Floridians hold a degree in
Criminology, out of 3,759,154 residents of that state who have at
least a bachelor's degree. This gives a rate of about 64
Criminology degree holders out of every 10,000 bachelor's degree
holders overall in Florida.

Meanwhile, for the United States as a whole, 98,475 people have a
degree in Criminology, out of 63,954,947 degree holders overall.
This gives a national rate of about 15 Criminology majors out of
every 10,000 bachelor's degree holders.

The location quotient of Criminology majors in
Florida is the ratio of these two rates: 64 ÷ 15, which is a
little above 4. So, there are about four times as many
Criminology majors per 10,000 degree holders in Florida as there
are in the nation as a whole. The map, then, shows the degree
with the highest location quotient in each state.

Taking our data and finding the most commonly held degree in
every state leads to a much more monotone result: In 35 states,
the most common major is Business Management and Administration,
which is also the most common major in the US as a whole: